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Home > Environment and services > Energy and housing

Energy and housing


A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM ¿ BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports ¿ Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes ¿ provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970¿2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK¿s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board¿s 'hot box¿. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371 

A guide to the development of BREDEM
This paper describes the development of the BRE Domestic Energy Model (BREDEM). It acts as a guide to the different versions of the model and indicates the likely direction of future developments. IP4/95 

An assessment of the cost-effectiveness and potential of heat pumps for domestic hot water heating
Indicates the circumstances in which the heat pump would be cost-effective, with the most promising potential markets in commercial premises and in dwellings with a high hot water use. IP8/85 

An energy-efficient refurbishment of electrically heated high-rise flats
Describes the results and lessons learned from the extensive monitoring of two blocks of high-rise flats which had a comprehensive package of energy efficiency measures included as part of a major refurbishment programme. IP20/89 

Assessing programs which predict the thermal performance of buildings
Discusses the problems of validating programs that predict the thermal performance of buildings, outlines sources of error and describes techniques to detect them. IP7/92 

BREDEM – BRE Domestic Energy Model
Describes a procedure for calculating the annual energy requirements of houses. It is designed to provide realistic results while being relatively simple to operate using a calculator or computer. BREDEM is based on many years' practical experience of what happens in buildings, and represents a synthesis of available information. BR66 

BREDEM-12: model description
This document describes the technical basis of BREDEM-12, the current annual version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update. BR438 

BREDEM-8: model description
This document describes the technical basis of BREDEM-8, the current monthly version of the BRE Domestic Energy Model. This model estimates energy consumption in dwellings, including estimates for space heating, water heating, cooking, lights and appliances. The principles behind the model are discussed and the equations are listed. Sufficient information to implement the model is given. 2001 update, with corrections May 2002. BR439 

BREDEM: The BRE Domestic Energy Model
A summary of the report BR66 'BREDEM - the BRE Domestic Energy Model - background, philosophy and description'. IP16/85 

Building regulations: conservation of fuel and power
Sets out, for dwellings, the 'energy target' method of complying with the 1990 Building Regulations in the form of a worksheet. The data needed for calculations, sample calculation and blank worksheet are also provided. Additional worksheets, packed in 50s, are available (reference AP 47). BR150 

Carbon emission reduction from energy efficiency improvements to the UK housing stock
In 1990 BRE published a report on energy use in buildings and carbon dioxide emissions, providing an account of the current state of knowledge for the UK. This report updates the earlier work for housing, taking account of new data and improved analytical techniques. The work follows three related lines of investigation: assessment of the cost-effectiveness of 28 individual energy-efficiency measures or products and the carbon savings that these could produce; assessment of the success of past energy-efficiency policies (ie grants for energy efficiency improvements); and development of future scenarios for energy use and carbon emissions of the housing stock. 70 pages.  BR435 

Domestic energy fact file
Four reports – Owner occupied homes, Local authority homes, Private rented homes, and Registered Social Landlord (RSL) homes – provide information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. They present tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998 which covers all tenures and provides a full discussion and explanation. These four reports replace the three tenure-based Domestic Energy Fact Files produced in 1994. AP139 

Domestic energy fact file
Presents in one volume some of the more important data on domestic energy consumption and the measures taken to use domestic energy more efficiently. BR220 

Domestic energy fact file
Updates the BRE Report 'Domestic energy fact file', providing information about energy use and energy efficiency in British homes up to and including 1991. The tables relate to national totals and will be of use mainly to government departments and others interested in research or planning at that level. BR251 

Domestic energy fact file 2003
Domestic energy use represents a large proportion of total national energy use and has risen from 25% of the total in 1970 to 30% in 2001. This edition updates the 1998 Fact File, presenting up-to-date information and introducing some new topics. It gathers in one volume data on important trends related to domestic energy use and, in particular, information on the measures taken to improve energy efficiency. The Fact File covers the period 1970–2001. BR457 

Domestic energy fact file: Registered Social Landlord (RSL) homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on RSL homes from the mid-1980s onwards it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR411 

Domestic energy fact file: local authority homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on local authority homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR409 

Domestic energy fact file: owner occupied homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on owner occupied homes it also draws comparisons with other tenures (primarily local authority homes) to illustrate important points. BR408 

Domestic energy fact file: private rented homes
One of four reports providing information on trends in energy use and energy efficiency in four sectors of the UK housing stock between 1970 and 1998. It presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File 1998, which covers all tenures and provides a full discussion and explanation. Although this report focuses on private rented homes it also draws comparisons with other tenures (primarily owner occupied homes) to illustrate important points. BR410 

Domestic energy factfile
This publications gathers together some of the more important trends related to domestic energy and the measures that have been taken to improve energy efficiency with which it is used. This edition covers the period between 1970 and 1996. BR354 

Domestic energy factfile: England, Scotland, Wales and Northern Ireland
Presents information on trends in energy use and energy efficiency of the housing stocks of England, Scotland, Wales and Northern Ireland from the mid-1970s to 1999. It forms part of the established series of publications that have focused thus far on Great Britain and on individual tenures. The report presents tables, graphs and charts equivalent to those in the Domestic Energy Fact File for Great Britain published in 1998, which provides a full discussion and explanation. BR427 

Domestic energy use and carbon emissions: scenarios to 2050
This paper describes five scenarios for energy consumption and carbon emissions from the domestic sector up to 2050. In addition to traditional energy efficiency measures, it looks at changes to heating systems to introduce low carbon technologies, the use of solar panels and photovoltaics, and increased low carbon electricity generation from the national grid. The costs and savings of each scenario relative to the reference scenario are examined. Overall cumulative costs range between £10 billion and £55 billion. In all scenarios the cumulative savings outweigh the costs by about 2012 indicating that, considered as an entire package, each of the scenarios would be cost-effective for society as a whole. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' BR 480 IP16/05 

Domestic warm-air heating systems using low-grade heat sources
The practicability of using warm-air distribution systems with low-temperature heat sources (eg, solar, heat pump and geothermal) has been demonstrated in a test room. A wide range of conditions were studied, and optimal air-supply rates and source temperatures for comfortable conditions determined. IP1/89 

Energy assessment for dwellings using BREDEM worksheets
Data is given for a 'worksheet' calculation of energy-use in dwellings using a simplified BREDEM methodology. The worksheet - one copy is included with the paper - is constructed for use with a hand-held calculator and IBM-compatible microcomputers. (Additional worksheets: AP 45). IP13/88 

Energy efficiency in dwellings
Levels of energy efficiency required for new dwellings by the Building Regulations and improvements to the efficiency of existing buildings, particularly considering the opportunities created by major refurbishments, are described. This Digest identifies the factors determining energy requirements and the methods used to assess energy efficiency. DG355 

Energy efficiency in new housing
Case studies show the marketing advantage of an energy efficiency specification for new housing, and how higher standards can be achieved at little or no extra cost. This paper advocates an integrated approach to energy-efficient design, and is intended for architects, designers and specifiers of new social and private housing. IP15/94 

Energy efficiency in the housing stock
BREHOMES is a model of energy use in the UK housing stock developed by BRE. Results from various surveys are presented in this paper which is addressed to all those concerned with improving energy efficiency in buildings. IP22/88 

Energy use and carbon dioxide emissions for UK housing: two possible scenarios
This paper presents the results of two possible scenarios for energy use and carbon dioxide emissions of the UK housing stock, developed using the BREHOMES model. One of them represents what is likely to happen if current trends continue, and is an update to the scenario in BRE Information Paper IP9/94. The second represents what could happen if the rates of uptake of energy efficiency measures increased. It shows that reductions in carbon dioxide emissions could be considerable: by 2020 they could amount to about 250 PJ (or 21 million tonnes of CO2) per year, representing roughly 13% of the corresponding energy use and CO2 emissions both now and, at current trends, in 2020. Furthermore, the cost savings if rates of energy efficiency improvement increase, are shown to be considerably greater than the extra expenditures when assessed over the period up to 2020. IP7/97 

Energy use in the housing stock
This paper provides information about energy use and energy efficiency trends in British homes since 1970. It demonstrates that energy efficiency measures have played a very important part in keeping average dwelling energy consumption relatively constant and in helping to reduce associated carbon dioxide emissions, while also making it possible to achieve improved levels of service. IP20/94 

Field studies on the effect of increased thermal insulation in some electrically heated houses
Describes measurements recorded in a study of local authority two-storey terraced houses taken to assess the practical benefits of an improved standard of thermal insulation. IP10/79 

Improving energy efficiency
This Good Repair Guide suggests some ways of improving insulation. It will be of interest to householders and builders involved in refurbishment. GR26 

Improving energy efficiency in housing
Provides a summary of the principle opportunities for improving energy efficiency in both new and existing housing. It partly draws on experience gained from projects carried out under the Energy Efficiency Demonstration Scheme. IP24/89 

Investing in energy efficiency: 1. Appraisal techniques and assumptions
Reviews several investment appraisal techniques and discusses how they can be used to assess the economic benefits of different energy efficiency measures in housing. IP17/86 

Investing in energy efficiency: 2. Existing housing
Uses the appraisal technique described in Information Paper 17/86 to assess the economic value of several ebergy efficiency measures applied to existing housing. Examples are given for loft insulation, wall insulation, double glazing and reflective foil behind radiators. The basic procedure is explained and sources of further information given. IP20/86 

Investing in energy efficiency: 3. New housing
The third of a short series of Information Papers concerned with the economic assessment of energy efficiency measures in housing. This paper examines the effects of installing additional thermal insulation or maximising solar energy heating in a 'standard' semi-detached house. IP22/86 

Investing in energy efficiency: Domestic hot water systems
This paper describes economic assessment of energy efficiency measures comprising the addition of an insulating jacket to a hot water storage system, installation of a shower for use instead of a bath, and installation of various heating system automatic controls. Sample calculations are given. IP1/87 

Mechanical installation of roof-mounted photovoltaic systems
This Digest gives guidance on installing and using photovoltaic systems on roofs. The guidance refers only to the mechanical installation of roof mounted integrated and stand-off photovoltaic systems; it provides best practice guidance on installation requirements and does not constitute fixing instructions. A classification system for photovoltaic systems is included, which incorporates illustrations of commercially available systems. Care, maintenance and inspection are also covered. This Digest has been prepared as part of a Partners in Innovation project funded by the Department of Trade and Industry. DG495 

Optimum start controls in modern low-energy buildings
Using the BRE low-energy office at Garston as an example, this paper describes how the incorporation of an optimum start control to meet the new Part Q of the Building Regulations, in a building insulated to the new standards of Part FF, means that special attention needs to be given to system design and installation. IP3/83 

Part L explained - The BRE guide
This guide will help architects and builders understand the energy performance requirements in the 2006 edition of Part L of the Building Regulations. It explains: - the background to the changes - the EU Energy Performance of Buildings Directive (EPBD) - the Regulations and approved guidance that implement the changes - designing buildings to meet the new carbon dioxide emission targets - new standards for work in existing buildings. It is presented in a concise and accessible format to help you understand the major changes in the Regulations and approved documents, and get up to speed without delay. It draws on BRE's close involvement in supporting the government work in drawing up the new Regulations. "The changes to Part L are radical and far reaching. This guide is designed to help designers and builders through the maze and to provide clear guidance in achieving cost-effective compliance with the new requirements." From the Foreword by Professor David Strong, MD of BRE Environment and Chairman of UK advisory group on implementation of the EBPD BR489 

Reducing carbon emissions from the UK housing stock
The UK Government set itself the goal of working towards reducing carbon emissions by 60% by 2050. This report explores the scope for achieving such reductions within the housing stock through energy efficiency measures and the uptake of low carbon technologies, such as renewable energy. It examines the current potential for such improvements, including their cost-effectiveness and assesses the effects that past energy efficiency policies have had. Extensive tabulations of hard-to-find data on cost-abatement analyses and past policies are included. Finally, it considers what could happen in the future. BR480 

The U-value of ground floors: application to building regulations
Describes a method for obtaining the U-value of ground floors (including floors of irregular shape) from their area and perimeter measurements. A table shows the thickness of insulation to be applied to a floor to achieve a U-value of 0.45 W/m2K. IP3/90 

The cost effectiveness of heat pumps in highly insulated dwellings: an assessment
It was found that savings in the running costs of electric heat pumps compared with most conventional central heating systems do not currently justify their extra capital cost. This paper discusses how, once a 40 per cent reduction in capital cost, a 43 per cent increase in performance, or smaller improvements in both, are achieved, the heat pump will be cost-effective as a replacement for oil-fired heating. IP7/85 

The scope for reducing carbon emissions from housing
The Government has set a target of reducing carbon emissions to the atmosphere by 60% by 2050. This Information Paper evaluates the scope for cost-effective reductions in emissions through energy efficiency measures in housing. From a starting point of 2001, it considers the potential for reductions by 2010, 2020 and 2050. It is derived from a wider BRE study, 'Reducing carbon emissions from the UK housing stock' (BR 480). IP15/05 

A practical guide to infra-red thermography for building surveys
This report is concerned with the thermal behaviour of buildings and their components, and describes methods and precautions to be adopted with the technique of infra-red thermography. BR176 

Assessing the effects of thermal bridging at junctions and around openings
This paper gives guidance on assessing the effects of thermal bridging at junctions and around openings in the external elements of buildings and how to assess their effect on the overall heat loss (or heat gain). It enables a satisfactory estimate of these heat transfers to be made for the purposes of carrying out building regulations compliance calculations. It supports the building regulations for the conservation of fuel and power in all three jurisdictions within the UK. The guidance is primarily intended for junction and opening details that are not as recommended in 'Accredited construction details' or MCRMA/EPIC guidance. This paper is a revision of IP17/01 which is now withdrawn. IP1/06 

BREEAM 98 for offices
BREEAM was first launched in 1990 to provide an environmental assessment and labelling scheme for buildings. It is updated periodically to ensure that the scheme continues to represent best practice. This publication describes the new version for offices. It provides a background to the scheme and the benefits that it can present as well as describing the structure and content of the assessment process. 46 pages. The main body of this report will still be applicable to BREEAM 2002 for Offices. Ratings checklists are normally updated annually and can be downloaded at http://www.breeam.org/offices  BR350 

BREEAM for new industrial units. Version 5/93
The BREEAM assessment methods for good building design can contribute to reducing pollution and to improving the global environment, the internal environment and occupants' health. This version of BREEAM assesses the environmental impact of industrial buildings, warehousing and non-food retail units. New edition due Spring 2006  BR252 

Comfort, control and energy efficiency in housing
In well designed and well managed buildings, comfort and energy efficiency can go together. Occupants should enjoy reasonable comfort under automatic control, but should also be able to alleviate discomfort manually when necessary. BRE studies show that improved controls for temperature, light and ventilation, will lead to energy savings. IP3/95 

Condensing boilers
Condensing boilers can usually offer valuable savings in energy compared to conventional boilers, the extra capital cost being recouped within one to five years. This Digest summarises system design, equipment selection, installation, commissioning and maintenance, and outlines economic appraisal of a new system. DG339 

Condensing boilers: a review of their performance in practice
Condensing boilers are more energy-efficient and environmentally friendly than conventional plant. This paper summarises the results of extensive studies of condensing boiler installations, and demonstrates that they can be a highly cost-effective way of saving energy. It will be of interest to building designers, owners and users, and to services specialists. IP19/94 

Conventions for U-value calculations (2006)
'Conventions for U-value calculations' guides the architect and specifier for calculating U-values by: - indicating the methods of calculation appropriate for different construction elements - roofs, walls, floors, basements, windows and doors - providing further information about using the methods - providing data relevant to typical UK constructions. Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types. This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. BR443 

Conventions for calculating linear thermal transmittance and temperature factors
This guide gives the conventions that should be followed by numerical modellers to produce consistent, reproducible results. For building regulation purposes two key modelling outputs, temperature factor and linear thermal transmittance, are identified. These key outputs will enable designers to confirm the adequacy of particular junction details and help with the development of novel solutions to improve the thermal performance of junctions. BR497 

Demonstration of re-use and recycling of materials: BRE energy efficient office of the future
This paper details a project to identify and study the practicalities of re-use and recycling, regarding commercial, operational and contractual issues. It provides valuable information for those concerned with demolition and waste management. IP3/97 

Domestic heat pumps: performance and economics
This report describes the performance of electrically driven air-to-water heat pumps in domestic systems. It is based on the results of full and part-load assessments at BRE and at trial installations; it also considers the economics of heat pump purchase and operation, alternative heat sources and types of heat pump. BR126 

Dynamic insulation for energy saving and comfort
A dynamic insulation system works by drawing outdoor air into a building through an insulation layer which is permeable to air. Heat, otherwise be lost by conduction, is recovered in the incoming ventilation air. This paper describes dynamic insulation systems and discusses energy savings and practicalities of building with them. It also covers practical design and buildability issues. The energy savings from the use of dynamic insulation are limited to the conduction loss expected for the same level of conventional insulation. The major benefit is improved comfort due to the ventilation air being preheated. IP3/03 

Electric heating in highly-insulated buildings
An assessment of the design, installation, operation and performance of electric heating in BRE's Low Energy Office building following its refurbishment. BR175 

Energy audits and surveys
Gives an overview of good practice in implementing energy audits and surveys in commercial, industrial and public-sector buildings IP12/92 

Energy consumption in public and commercial buildings
An appraisal of the total delivered energy used to supply building services to UK public and commercial buildings in 1991. Estimates of the split of that energy between the different services and fuels are given for each of the major economic groups. This paper will interest those wanting a general overview of buildings-related carbon dioxide emissions and energy use. IP16/94 

Energy economy and heat retention
One of a series of reports following seminars involving the presentation and discussion of five of the six drafts of the Interpretative Documents. These IDs will provide the links between the Essential Requirements of the Directive and the mandates for producing European Standards, Technical Approvals and other technical specifications. BR179 

Energy efficiency in schools
Schools could save money and benefit the environment if their buildings were made more energy-efficient. It is not widely recognised that many energy-saving measures are simple and inexpensive, and that they could be cost-effectively incorporated in a programme of routine maintenance and refurbishment. IP2/94 

Energy use by office equipment: reducing long-term running costs
This paper explains how a better understanding of the power needs of office equipment can lead to cost savings through the use of energy-efficient equipment and a reduction in office cooling requirements. IP10/94 

Energy use in buildings and carbon dioxide emissions
About half of the total UK emissions of the major greenhouse gas, carbon dioxide, is attributable to buildings; of this, about 60% is from dwellings. This report analyses and reviews evidence of emissions in the UK and the world as a whole, and considers the potential for reducing them. BR170 

Energy use in office buildings
Reviews average and 'good practice' energy use and costs in four types of office building. Analyses energy consumption by various end-uses in typical and good practice buildings. IP20/92 

Energy-efficient factories: design and performance
BRE's assessment of, and the increased energy efficiency that can be achieved in, factories built with higher standards of insulation than those required by the Building Regulations. IP13/89 

Facilities Managers' Energy Primer
This guide is written for anyone whose job involves energy management. It considers how to integrate energy efficiency into all aspects of the management of a facility. It shows how to reduce energy consumption and running costs and gives guidance on increasing awareness of energy conservation. EP46 

Financial benefits of energy efficiency to housing landlords
A new study shows how housing landlords can benefit financially by investing in energy efficiency measures. For every £1 potentially saved by tenants, a similar saving is available to the landlord in previously unquantified management and maintenance costs. This information will be of particular interest to housing managers and others responsible for targeting investment in social housing. IP11/94 

Future energy use and carbon dioxide emissions for UK housing: a scenario
This paper describes a method of estimating future energy use and carbon dioxide emissions for the United Kingdom housing stock and presents the results of a scenario based on this method. The method relies on BRE's energy balance model (BREHOMES) and the resulting scenario can be used to judge progress towards the UK's aim, under the Climate Change Convention, of returning carbon dioxide emissions to 1990 levels by the year 2000. IP9/94 

High-tech mixed-use buildings: attitudes to energy efficiency
An overview of market research into high-tech, mixed-use office and industrial developments. Attitudes to energy efficiency and environment are examined in relation to the process of building selection and development. IP1/90 

Improving the energy-efficient performance of high-rise housing
This paper draws on a survey of high-rise housing owned by ten local authorities, highlights some of the problems and suggests strategic improvements in the way buildings are refurbished and managed. IP4/91 

Industrial building refurbishments: opportunities for energy efficiency
Describes the results of market research into refurbishment, motivation and attitudes. Assesses opportunities for energy efficiency and discusses why this is often neglected. Relevant to policies, planning and project proposals of anyone involved in refurbishment of industrial buildings. IP2/93 

Installing thermal insulation
This Good Building Guide gives practical help in the different methods of building insulation into each part of the house (eg ground floors, external walls, windows/doors and roofs). Deficiencies in detailing that allow air leakage and thermal bridging will cause condensation, mould growth and excessive energy use in the finished house. Following the advice in this Good Building Guide will result in a well-insulated house that is warmer to live in, cheaper to run and better for the environment. Part 1 covers: General principles of preventing thermal bridging and air leakage, Ground floors, Pitched roofs and rooms-in-the-roof. Part 2 covers: External cavity walls, Windows and doors, Further reading. GG68 

Low energy cooling
This publication contains two reports from the International Energy Agency's Annex 28 to assist with the design of low energy cooling systems. It provides guidance on the initial selection of suitable low energy technologies, and presents a collection of simplified tools based on design charts and tables, and practical guidance, to assist with early design development of a technology. EP56 

Micro-wind turbines in urban environments
There is little experience of the operation of small wind turbines mounted on domestic buildings in urban environments and little data on their performance in terms of power generation, service life and maintenance. This study shows that, in addition to the initial embodied carbon and efficiency of the turbine, the payback period is highly sensitive to local wind conditions, transport costs, and the maintenance requirements and service life of the turbine. It reveals large variations in output of micro-wind turbines in a city such as Manchester and a windy location such as Wick in northern Scotland, and between the outskirts and town centres in windy locations such as Portsmouth and Wick. In windy locations, micro-wind turbines can generate enough energy to pay back their carbon emissions within a few months or years but in large urban areas, micro-wind turbines may never pay back their carbon emissions. Life cycle costing suggests that, even in favourable urban locations, financial payback is unlikely for all but the most durable, efficient and low maintenance turbines. This work confirms the need for a more rigorous method for estimating the electricity generated from building-mounted micro-wind turbines and for research and innovation in technology, planning and urban design to maximise the effectiveness of the turbine installations. Features / Benefits Provides a rigorous analysis of all the factors that influence the power that small wind turbines can generate in urban areas Studies the whole life costs and carbon emission costs of micro-wind turbines Case studies for three locations - Manchester, Wick and Portsmouth Readership Architects, builders, services engineers, planners, energy companies, local authorities, turbine manufacturers, government agencies FB17 

Minimising refrigerant emissions from air conditioning systems in buildings
Tells building owners, operators and their consultants what they can do to minimise leakage of harmful refrigerants (CFCs and HCFCs). IP1/94 

Modelling the performance of thermal mass
This Paper looks at the impact on thermal and energy performance of: building envelope, internal heat gains, operating period, ventilation, thermal mass and control. It highlights the importance of reducing infiltration and conduction losses when refurbishing a building to include thermal mass, the difference between winter mid-season and summer operation and the impact of the night cooling strategy selected on energy use. It considers the effect on acoustics and lighting of the introduction of exposed ceilings. It also gives guidelines for modelling thermal mass performance. BRE Digest 454 gives guidance on incorporating thermal mass into office buildings. IP6/01 

Non-domestic buildings energy fact file
This document gathers key statistics relating to structure and energy use of the UK’s non-domestic buildings. It includes historical information on the way energy is used and how this relates to carbon dioxide emissions; the occurrence of building services; and the structure of the stock. BR339 

Performance of HVAC systems and controls in buildings
Proceedings of a symposium held at BRE, Garston, on advances in the understanding of complex interactions of HVAC systems, their controls and the buildings in which they are installed, and the role this plays in the realisation of greater energy efficiency. BR64 

Performance of a PSA trial energy management system
Provides a detailed assessment of energy and other savings achieved in a medium-sized conventionally heated Government office building after the installation of a microprocessor-based energy management system (EMS) by the Property Services Agency. IP2/85 

Performance of air-conditioning systems with alternative refrigerants
A new EC Regulation is being considered that may prohibit the continued use of CFCs for maintaining existing refrigeration systems and the use of HCFCs in new systems. This paper outlines the options for replacing CFCs and HCFCs in building air-conditioning systems, and reports recent findings from BRE work to investigate the performance of systems converted to an alternative refrigerant. This paper will be of interest to building owners and operators, architects, and building services engineers and consultants. IP6/98 

Phase-out of CFCs and HCFCs: options for owners and operators of air conditioning systems
This paper gives owners and operators of air conditioning systems advice on options for coping with the CFC and HCFC phase-outs and end-use controls. IP14/95 

Reliability and performance of solar-collector systems
Advice for design and installation of systems using liquid heat transfer. This Digest describes some of the more common problems and their possible solutions, and gives guidance on methods of checking the operation of systems. DG254 

Reliability of underground heat mains in the UK
Provides objective data on the reliability and costs in use of heat distribution networks in districty heating schemes throughout the country, based primarily on the experience and records of owners and operators. IP1/86 

Retail warehouses: the potential for increasing energy efficiency
A description of an assessment of opportunities for energy-efficient design and retrofit for industrial shed-type retail warehouses. The assessment related to cost savings and environment benefits, and resulted from the examination of five major retail operations. IP8/90 

SBEM for non-domestic buildings
SBEM, the Simplified Building Energy Model, is a tool for calculating the energy used by a non-domestic building. It has been developed in response to the requirements of the EU's Energy Performance of Buildings Directive (EPBD). This information paper will help designers, building services engineers, facilities managers and building control officers to understand what SBEM is and how it works as a core energy calculation tool. It also describes an interface tool (iSBEM) for presenting the resulting data and a tool (BRUKL) for checking for compliance with the requirements of the EPBD. Features / Benefits ~Clear explanation of how SBEM works when carrying out building regulation compliance checks and energy ratings ~Describes the basis of SBEM, the input information it requires, from where this information is derived, and which energy consumption issues are included ~Considers use of SBEM for other applications outside the compliance checks Readership Architects, building services engineers, facilities managers, building control officers and other construction professionals concerned with energy performance of buildings IP2/07 

Selection of building energy management systems
Examines the features, attributes and limitations of available systems and discusses the factors affecting their suitability for particular types of application from the point of view of the user. It considers specification, application software, the man-machine interface, hardware, and supply and cost factors. IP6/85 

Small scale, building integrated, wind power systems
This Information Paper provides an overview of the key issues for government, regulators, suppliers and designers in enabling greater use of small scale wind power. It also gives brief overviews of companies and wind power systems. It is based on the proceedings of the 2005 BRE/British Wind Energy Association Conference. The UK's renewable energy target for 2010 will be mostly met through large scale renewable energy projects. However, small scale installations will also have an important role to play. Renewable energy is an indispensable factor in developing sustainable communities and small scale production is an effective way for a community to produce its own electricity. At the right scale, and on appropriate sites, wind energy is one of the most economic and rapid means of reducing carbon dioxide emissions. IP12/05 

Solar energy in urban areas
The exploitation of solar energy in cities is difficult owing to a combination of factors. For example, obstructing buildings can block solar access. This paper discusses the problems and shows how they can be overcome. It will be of interest to architects, engineers, consultants and urban planners. IP5/01 

The BRE low-energy office: an assessment of electric heating
The conclusions drawn from an assessment of the costs and benefits following installation of electric heating in BRE's Low Energy Office. IP16/90 

The Carbon Performance Rating for offices
This Digest describes a target-based method of assessing the likely energy effiency of a non-domestic building design. It is referenced in the 2002 edition of Approved Document L2 of the Building Regulations which includes a simple assessment method to addrees the design of air conditioning and mechanical ventilation systems. The method described in this Digest extends that method to include heating and lighting design. Both methods have been developed specifically for office building services design, and to address carbon emission as a Carbon Performance Rating. DG457 

The assessment of U-values for insulated roofs
Reports the results of some measurements on insulated ceilings carried out for BRE in the Agrement Board”s 'hot box”. It discusses their relationship with conventional calculation procedures for the assessment of U-values, and identifies the need for more information on air speeds in loft spaces. IP3/81 

The gas engine driven heat pump dehumidification system at the Farnborough Recreation Centre - an assessment
A 12-month monitoring period has demonstrated that the performance of a gas engine driven dehumidification system for an indoor swimming pool at the Farnborough Recreation Centre has exceeded design expectations and achieved a 70% saving in heating energy. The system itself and the economics of it are described here. IP14/86 

The safety and environmental requirements of new refrigerants
This paper gives information and guidance on the safety and environmental requirements that are associated with the use of new refrigerants to replace CFCs and HCFCs in building air-conditioning systems. It also alerts designers, owners and operators to the requirements of the revised British Standard on refrigeration safety (BS 4434:1995) and to their statutory duties under UK health and safety legislation. IP16/95 

The thermal efficiency of large oil-fired boilers
Gives the results of tests on seven boilers with rated outputs from 111 to 5689 kW to determine the factors affecting their thermal efficiency when run at less than full load. The results can be used to achieve energy savings over a wide range of boiler types. BR140 

Thermal insulation: avoiding risks
This report represents an update of the BRE guide first produced in 1989 and extensively revised in 1994. The approach of these earlier editions, highlighting the link between risks, causes and solutions, has been retained. This updated edition contains a number of revisions resulting from developments in research, changes in materials, construction techniques and the building regulations. The guide has been prepared to support the building regulations for the conservation of fuel and power. The information in this guide represents the recommendations of BRE on good design and construction practice associated with thermal standards. It discusses the more important technical risks associated with meeting the requirements of the building regulations for thermal insulation. Technical risks are highlighted and these are followed by actions that could be taken to avoid the risk. BR262 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 1 defines thermal mass and outlines its effects in a number of scenarios. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/1 

Thermal mass in office buildings
This Digest describes how thermal mass can be designed into a building, the options available, and the strategic decisions that may be made in design that require understanding between the design team. Although mainly relevant to non-domestic buildings, it is also appropriate to refurbishment schemes. Part 2 discusses the effective incorporation of thermal mass into building designs. A companion Information Paper (IP 6/01) deals with modelling the performance of thermal mass to minimise annual energy use while maintaining occupant comfort.  DG454/2 

Trends in thermal comfort research
Among the many topics covered in this review are: the discrepancy between field study and climate chamber predictions for thermal comfort, the effects on thermal comfort of air movement, thermal radiation, clothing and physiology, thermal comfort indices, instrumentation developments, the subjective assessment of the environment, and energy conservation. BR266 

U-values for basements
Gives data for determining the insulation needed to achieve U-values of 0.45 W/m2K for basements, as currently required by the Elemental Method of satisfying the 1995 edition of the Building Regulations. IP14/94 

VAV systems
VAV air conditioning systems are considered to be more energy efficient than many other types of air distribution system because they can minimise fan energy consumption at part load operating conditions. However, previous work by BRE for DETR has shown that the predicted energy savings are not achieved in practice due to factors such as incorrect fan static pressure sensor location, use of inefficient fan speed control methods and system installation effects. This report presents the results of a critical review of a number of papers, reports and relevant guidance documents on variable air volume (VAV) air conditioning systems published in the UK and USA. In each case an abstract is given with an interpretation of the main points of each document. The report concentrates on the role of the building engineering services designer with responsibilities for the complete package, including the construction commissioning, testing and maintenance of the installation. To increase awareness of design techniques for enhancing the energy efficiency of VAV air conditioning systems, each review identifies specific and definitive (rather than general) design information. BR371